This invention is directed to article handling apparatus, and more specifically to apparatus for loading and unloading a plurality of like articles with respect to a plurality of trays for storage and/or transport between various handling and/or utilization stations.
While apparatus in accordance with the invention may find utility in a number of applications, the ensuing description will be facilitated by particular reference to a system for handling can ends.
In the manufacture of containers such as beverage cans or the like, a great number of can end parts are required. Generally speaking, modern aluminum beverage container bodies present but a single open end and hence require but a single end closure piece or "can end", as they are called in the trade. Apparatus have heretofore been devised for handling, stacking, packaging and unpackaging can ends during their manufacture and for their further processing, both prior to and up to their final assembly with can bodies. A number of individual steps or stations can be utilized in processing can ends prior to this final assembly. For example, at one station, the ends may be suitably cleaned and sterilized for use in beverage or other food containers. At yet another station a protective inner lining material or substance may be applied for use in some beverage and food container applications. Yet another operation may involve the fitting of pull rings or tabs to tear-away openings or the like, as in the case of so called "flip-top" or "pop-top" type containers.
Accordingly, modern container preparation and assembly operations require that numerous relatively small disk-like can ends be transported from one station to the next in a more-or-less continuous process up to, and including, the final assembly thereof with can bodies. Generally speaking, however, such final assembly does not take place until the filling of the container or body by the end user. Accordingly, processing of the can ends separate from the can bodies prior to the filling process is generally contemplated.
It should also be appreciated that modern can ends have a slight curl or lip, as well as the frequently present tear-away top portion with graspable tab, ring, or the like. The lips or curls tend to make can ends nestable in generally flat, coaxial, side-by-side arrangement. However, the tabs or rings tend to cause the can ends to tilt or cant somewhat. That is, the graspable tabs or rings for removing the tear-away opening tend to impart a spring-like action to a stack of otherwise nested or closely axially placed ends, which tends to cause the ends to spread apart somewhat and at least the endmost members to tilt or cant, or perhaps come apart entirely from the remaining members of a stack.
Furthermore, it has become important to provide a reasonably accurate count of can ends for handling in individual, predictably-sized groups or stacks, or, as they are called in the art "sticks". It should be appreciated that modern operations require that on the order of hundreds and sometimes even thousands of ends be processed per minute to maintain the desired efficiency of operation. Accordingly, it will be appreciated that the accurate and rapid handling of large numbers of groups or sticks of can ends is an important consideration in achieving such efficient operation. Needless to say, errors in counting and handling and transporting such can end sticks or groups can damage equipment and/or cause a shutdown of extremely large and expensive processing systems or factories. The attendant delay can be extremely costly in terms of idle personnel and machinery, as well as in terms of delayed processing of product, such as by causing failure to meet required delivery dates or the like.
Accordingly, we have devised novel and patented machinery and other apparatus for facilitating the accurate and rapid handling of large numbers of can ends. Examples of these modern can end handling systems are shown for example in a number of prior patents which are assigned to the assignee of this application, for example: Mojden et al. U.S. Pat. Nos. 3,165,218; 3,337,064; 3,523,602; 3,545,631; 3,595,372; 3,618,550; 3,722,741; 3,754,635; 3,878,945; 4,000,709; 4,364,466; 4,537,010; 4,537,550; 4,580,938; and 4,979,870.
We have now developed a novel and improved automatic tray loading and unloading and storage system for can ends, which advantageously is adapted in effect, to compensate for differences in the supply and flow of can ends between one station and the next in a multiple station processing plant as described hereinabove. Advantageously, our system greatly facilitates such overall compensation between various stations by permitting automatic loading of ends upon processing thereof at one station onto pallet-sized trays, which may then be readily transported by normal pallet handling methods and apparatus to one or more other stations for further processing of the can ends.
Advantageously, our system permits ready storage of excess can ends from one station until they are needed for further processing at other stations. Hence, any oversupply or shortage developed because of a shutdown or slow down of one station in a multiple station operation need not affect the continued operations of the remaining stations. Hence, our novel system permits the above-described compensation in a multiple station processing plant to thereby optimize the efficiency of operation within the plant. In effect, our system compensates between varying rates of supply of can ends as they are delivered from any given processing station and different and also varying rates of demand for can ends at other processing stations. That is, any excess supply is absorbed, and any shortage is made up, by our system.